Underwater firearms for fishing or for protection from large sea creatures are well known and take many forms. Various examples are described in U.S. Pat. Nos. 3,618,244; 3,664,052; 3,721,031; 3,747,247; 3,838,532; 3,871,120; and 4,100,692. They all have in common the fact that a gun powder charge held in a substantially conventional cartridge or shell is employed as the source of explosive. The cartridge is fired by bringing its primer in contact with a pin.
Many of these prior art devices are triggerless, that is, they fire automatically on impact with the target. The act of striking the target forces the firing pin against the cartridge primer or vice versa. Various sliding weights, springs, and inertial latches have been used on some versions to improve performance. For safety reasons they are constructed to require a solid hit against the target before they fire.
While some of these triggerless units are very simple in construction, they offer only limited protection or fishing opportunity to the user. The fact that they must hit the target before they will fire is a significant restriction and may expose the user to dangerous situations under circumstances where the target fish or the threatening shark does not present a clear chance for a solid hit until it actually attacks the user.
To overcome this problem, some prior art units are trigger fired, much as in a conventional firearm. They do not depend upon inertial forces resulting from contact with the target. These units have a firing pin which is cocked against a compressed spring. When the trigger is pulled, the compressed spring drives the firing pin into the cartridge primer. Such a unit is described, for example, in U.S. Pat. No. 3,618,244 where the exploding cartridge is used to propel a tethered spear head. A significant limitation of prior art triggered units is their complexity, limited safety features, poor reliability, and high cost. Thus, a need continues to exist for improved underwater firearms for fishing or defense against predatory sea creatures.
Accordingly, it is an object of the present invention to provide an improved underwater firearm of simple construction which is easy to operate, has a positive safety, is reliable in operation and simple to maintain, and which has a minimum of moving parts.
It is a further object of the present invention to provide an improved trigger fired underwater firearm which does not require contact with the target to fire.
It is an additional object of the present invention to provide an improved trigger fired underwater firearm which is particularly adapted to kill sharks.
It is a further object of the present invention to provide an improved underwater firearm which has a shape easily manipulated and aimed underwater and which has sharp points protruding around the muzzle for engaging the surface of the target so as to prevent slipping and regulate the distance of the gun from the target.
It is an additional object of the present invention to provide an improved underwater firearm which may be largely made of inexpensive durable materials including plastics.